Mass spectrometer



FIG. 1 is a front, top and left side perspective view of a mass spectrometer showing the design;

FIG. 2 is a front, top and right side view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof; and,

FIG. 7 is a top view thereof. 

CLAIM I claim the ornamental design for a mass spectrometer, as shown. 